Compilation issue of Ibex-lib on gwin64-7.3.0

[le-sigwal]

https://al.liammig.bzh/ibex/ftq/#IBX_VR_000001

As "/wd4244" compilation option is MSVC specific, the current solution only authorize MSVC compilation chain on Windows. This explain why compilation failed with MinGW64 tool chain.

The correction allows MinGW64 and keeps the same behavior for MSVC tool chain.

[le-sigwal]

⚠️ Error in [mwin32] AppVeyor job, [mwin64] in OK (cf 52378436)

• [mwin32] Environment: CMAKE_PLATFORM=Visual Studio 14 2015, IBEX_PATH=C:\Program Files (x86)\IBEX, platform=x86, CPPUNIT_DIR=C:\tools\vcpkg\installed\x86-windows
• [mwin64] Environment: CMAKE_PLATFORM=Visual Studio 14 2015 Win64, IBEX_PATH=C:\Program Files\IBEX, platform=x64, CPPUNIT_DIR=C:\tools\vcpkg\installed\x64-windows

There is a problem with winflexbison intallation:

choco install winflexbison
Chocolatey v0.10.15
Installing the following packages:
winflexbison
By installing you accept licenses for the packages.
Progress: Downloading winflexbison 2.4.9.20170215... 100%
winflexbison v2.4.9.20170215 [Approved]
winflexbison package files install completed. Performing other installation steps.
WARNING: Url has SSL/TLS available, switching to HTTPS for download
Downloading winflexbison 
  from 'https://sourceforge.net/projects/winflexbison/files/old_versions/win_flex_bison-2.4.9.zip'
ERROR: The remote file either doesn't exist, is unauthorized, or is forbidden for url 'https://sourceforge.net/projects/winflexbison/files/old_versions/win_flex_bison-2.4.9.zip'. Exception calling "GetResponse" with "0" argument(s): "The request was aborted: Could not create SSL/TLS secure channel." 
This package is likely not broken for licensed users - see https://chocolatey.org/docs/features-private-cdn.
The install of winflexbison was NOT successful.
Error while running 'C:\ProgramData\chocolatey\lib\winflexbison\tools\chocolateyInstall.ps1'.
 See log for details.
Chocolatey installed 0/1 packages. 1 packages failed.
 See the log for details (C:\ProgramData\chocolatey\logs\chocolatey.log).
Failures
 - winflexbison (exited 404) - Error while running 'C:\ProgramData\chocolatey\lib\winflexbison\tools\chocolateyInstall.ps1'.
 See log for details.
Command exited with code 404